Protective cap for thermal grease of heat sink

ABSTRACT

A protective cap for use with a heat sink, includes a cover plate for enclosing thermal grease on the heat sink, and a plurality of strengthening ribs positioned on the cover plate. The strengthening ribs resist the heat sink to prevent the thermal grease from being pressed against the cover plate.

BACKGROUND

1. Technical Field

The present invention relates to a heat sink having a removable protective cap for enclosing thermal grease on the heat sink.

2. Description of Related Art

A heat sinks is typically used to dissipate heat generated by a central processing unit (CPU). Thermal grease may be applied to a bottom surface of the heat sink before being mounted to a CPU module to improve heat conductivity between the heat sink and the CPU module. However, thermal grease cannot be directly applied to the heat sink in advance because it is not solid at ambient temperature, may contaminate surrounding articles, or be contaminated by dust or foreign particles before the heat sink is mounted to the CPU module. A removable protective cap for enclosing thermal grease, disclosed in U.S. Pat. No. 6,049,458, includes a periphery removably attached to a bottom surface of a heat sink around the thermal grease, and a middle protrusion defining a cavity receiving the thermal grease. The protective caps are commonly made of plastic and may twist under pressure, and press against the thermal grease, affecting the heat conductivity between the heat sink and the CPU module.

Therefore, a new protective cap for thermal grease of a heat sink is desired to overcome the above-described deficiencies.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an embodiment of a protective cap for enclosing thermal grease on a heat sink;

FIG. 2 is an assembled, isometric view of the protective cap mounted on the heat sink of FIG. 1; and

FIG. 3 is a sectional view of the protective cap enclosing thermal grease on the heat sink of FIG. 1, taken along line III-III.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is an isometric view of an embodiment of a protective cap 30 for thermal grease 15 applied on a heat sink 10. The heat sink 10 includes a metallic base plate 11 and a plurality of metallic heat dissipating fins 14 positioned on a top face of the base plate 11. A bottom face 113 is configured to contact a heat source. The thermal grease 15 is spread on a middle portion of the bottom face 113. Corners of the base plate 11 have no thermal grease. Two heat pipes 13 are positioned between the base plate 11 and the heat dissipating fins 14.

The protective cap 30 includes a cover plate 31 having a shape similar to a shape of the bottom face 113. A side plate 32 extends from the perimeter of the cover plate 31. The cover plate 31 and the side plate 32 cooperatively form a cavity to cover the base plate 11. A plurality of strengthening ribs 33 are formed at corners of the cover plate 31 and extend to an inside space of the cavity to connect with the side plate 32. The strengthening ribs 33 are configured to contact the bottom face 113 to prevent the thermal grease 15 from being pressed against the cover plate 31. In one embodiment, a plurality of cutouts 321 is defined in the sidewall to allow the protective cap 30 to fit over heat pipes 13 positioned between the base plate 11 and the heat dissipating fins. In the illustrated embodiment, two cutouts are defined in two opposite walls of the side plate 32 corresponding to the heat pipes 13. In one embodiment, a height of the strengthening ribs 33 is larger than a height of the thermal grease 15, and a width of the cutouts 321 is slightly less than a width of the heat pipes 13.

Referring also to FIGS. 2 and 3, the protective cap 30 is pressed onto the base plate 11 until the heat pipes 13 are received in the cutouts 321 and the strengthening ribs 33 resist the bottom face 113. The strengthening ribs 33 prevent the thermal grease 15 from being pressed against the cover plate 31.

It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structure and function of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A protective cap for enclosing thermal grease spread on a base plate of a heat sink, comprising: a cover plate; and a plurality of strengthening ribs formed on the cover plate to resist the heat sink for preventing the thermal grease from being pressed against the cover plate.
 2. The protective cap of claim 1, wherein a side plate extends from a perimeter of the cover plate, the cover plate and the side plate cooperatively form a cavity to cover the base plate; the strengthening ribs extend to an inside space of the cavity.
 3. The protective cap of claim 2, wherein the strengthening ribs extend to connect with the side plate.
 4. The protective cap of claim 1, wherein the strengthening ribs are positioned at corners of the cover plate.
 5. A heat sink for dissipating heat generated by a heat source, comprising: a base plate having a bottom face and configured to contact the heat source; thermal grease applied on the bottom face; and a protective cap for enclosing thermal grease comprising a cover plate and a plurality of strengthening ribs positioned on the cover plate to resist the bottom face for preventing the thermal grease from being pressed against the cover plate.
 6. The heat sink of claim 5, wherein a side plate extends from a perimeter of the cover plate, the cover plate and the side plate cooperatively form a cavity to cover the base plate; the strengthening ribs extend to an inside space of the cavity.
 7. The heat sink of claim 6, wherein the strengthening ribs extend to connect with the side plate.
 8. The heat sink of claim 6, further comprising a plurality of heat pipes positioned on a top face of the base plate; the side plate comprises a plurality of cutouts corresponding to the plurality of heat pipes; the plurality of heat pipes are received in the cutouts to fix the protective cap onto the heat sink.
 9. The heat sink of claim 5, wherein the cover plate has a shape similar to a shape of the bottom face, the strengthening ribs are positioned at corners of the cover plate; the thermal grease is spread in a middle portion of the bottom face.
 10. The heat sink of claim 5, wherein a height of the strengthening ribs is larger than a height of the thermal grease. 